The present invention relates to a sliding track assembly for drawer, and more particularly to a durable sliding track assembly, which produces less friction resistance during loading of the inner rail, and enables the inner rail to be quickly and easily loaded or unloaded.
U.S. Pat. No. 5,577,821 discloses a sliding track assembly for drawer. This structure of sliding track assembly is functional, however it still has drawbacks. As illustrates in FIGS. 1 and 2, the stop member comprises two retaining portions respectively backwardly protruded from two upright side blocks thereof for engagement with two side walls of the second sliding bearing to hold down the second sliding bearing in the intermediate rail when disconnecting the inner rail with the drawer from the intermediate rail, preventing the second sliding bearing from bearing pushed backwards or damaged when inserting the inner rail into the second sliding bearing in the intermediate rail to reload the drawer. The drawback of this design is that the retaining portions of the stop member wear quickly with use, and tend to be permanently deformed. When the retaining portions of the stop member start to wear, or are permanently deformed, the stop member can not positively hold down the second sliding bearing when disconnecting the inner rail with the drawer from the intermediate rail.
FIGS. 3 and 4 show a sliding track assembly according to U.S. Pat. No. 5,722,750. According to this design, the stop member comprises two backwardly extended rear locating plates adapted for holding down the second sliding bearing. The locating plates each have a beveled rear guide edge adapted to guide the second sliding bearing into engagement with the locating plates, and a notch extended through the respective two opposite side walls. The notch separates the rear end of the respective locating plate into an upper part and a lower part, and enables the upper part of the rear end of the respective locating plate to be forced downwards when the front positioning portions of the bottom wall of the second sliding bearing are moved into engagement with the locating plates. This design is still not satisfactory in function. The front positioning portions of the bottom wall of the second sliding bearing may be erroneously engageed into the notches the locating plates due to improper application of force, affecting normal functioning of the sliding track assembly.
The present invention has been accomplished to provide a sliding track assembly for drawer, which eliminates the aforesaid problems. In one embodiment of the present invention, the sliding track assebmly comprises an outer rail fixedly mounted inside a desk, an intermediate rail carried on a first sliding bearing and moved in and out of the outer rail, an inner rail carried on a second sliding bearing and moved with a drawer in and out of the intermediate rail, and a stop member installed in the intermediate rail to limit forward movement of the inner rail relative to the intermediate rail, wherein the stop member has two rear retaining frames for holding down the second sliding bearing when disconnecting the inner rail from the intermediate rail, the rear retaining frames each having an upright retaining wall for engagement with opposite side walls of the second sliding bearing, the upright retaining wall of each rear retaining frame recessed portion on the respective side wall of the second sliding bearing, the upright retaining walls of the rear retaining frames being respectively spaced from the upright side walls of the intermediate rail by a gap, which enables the upright retaining walls of the rear retaining frames of the stop member to be respectively forced outwards to minimize friction during loading of the inner rail with the drawer on the intermediate rail. In another embodiment of the present invention, the sliding track assembly sliding track assembly comprises on outer rail, an inner rail, a sliding bearing coupled between the outer rail and the inner rail, and a stop member installed in the outer rail, the stop member comprising two upright side blocks, which stop the sliding bearing from being moved out of the outer rail, two rear retaining frames adapter to hold down the sliding bearing when dosconnecting the inner rail with the second device from the outer rail, preventing the sliding bearing from being pushed backwards or damaged when inserting the inner rail into the sliding bearing in the outer rail to reload the drawer, the rear retaining frames of the stop member each comprising an upright retaining wall respectively backwardly extended from the upright side blocks of the stop member and adapted for engagement with two opposite side walls of the sliding bearing, a bottom retaining wall adapted for engagement with the front positioning portions of the bottom wall of the sliding bearing, and a longitudinal split disposed between the upright retaining wall and the bottom retainig wall for enabling the bottom retaining wall to be forced outwards to minimize friction resistance during loading of the inner rail with the drawer on the outer rail, the bottom retaining wall of each rear retaining frame of the stop member comprising a raised portion adapted for engagement with a recessed portion on the front positioning portions of the bottom wall of the sliding bearing.